US 2010/0104809 A1 relates to a roof covering providing a solar reflectance of at least 70% and a thermal emittance of at least 0.75. The known roof covering provides a protective coating on an upper surface of a substrate, which coating is a dried film of an aqueous composition comprising a water resistant styrene-acrylic emulsion polymer, at least one reflective pigment, flame retardant, and lightweight filler having a density of not more than 0.084 g/cm3. At least partially embedded in the protective coating, there is provided a layer of particles to provide a solar reflectance of at least 70% and a thermal remittance of at least 0.75. The concept of the prior art coating on the substrate is to predominantly reflect the radiation energy and thus, avoid heating of the coating and the substrate.
In the prior art there are also known surface coatings which cooling effect is based on the concept of reducing the surface area making contact with a bare foot and thus, lowering the surface temperature that is felt by the person walking on the product with bare feet. Such coatings may reduce the temperature subjectively felt by the person walking on the surface during sun burning hours. However, these products do not really reduce the actual temperature on the surface of the coated substrate.